Helping users carrying heavy loads has long been a need in many circumstances. For example, soldiers in the field, firefighters, police officers, antiriot squads, but also construction workers, and hikers, are often faced with the problem of carrying heavy loads, sometimes over long distances. Solutions to such a problem that have been proposed over the years, have sometimes taken the form of a portable structure, also known as an exoskeleton, to be worn by the user, sometimes as a complement to the legs, sometimes through the legs and torso.
U.S. Pat. No. 8,474,672 by Keith teaches an arrangement for replaceably supporting a backpack having a load on the back of the user and transferring the load of the backpack to the ground by way of the legs of the user while allowing the user to take steps unhindered. However, such arrangement does not allow for flexibility of the legs, when the user often needs to be able to squat.
Most of the solutions proposed are powered, i.e. comprise motor driven mechanism for helping the carrying of the load. For example, U.S. Patent Application No. 2011/0264014 (Angold et al.) teaches a portable load lifting system.
Other prior art provides extension frames which extend from an exoskeleton trunk and are configured to hold a load in front of a person wearing the exoskeleton, as taught by U.S. Pat. No. 8,057,410 B2 (Angold et al.). While useful, such a configuration does not provide for easy manipulation of a load by the wearer over a long distance. Additionally, such a device does not address the problem of unequal weight distribution about an exoskeleton trunk, which could cause significant balancing problems for a wearer of the exoskeleton, while the wearer is stationary as well as walking.
Therefore, most of the prior art consists of powered exoskeletons, which, although useful in certain circumstances, may be inadequate, due to the excess weight, costs, dependence on power supply, and lack of ergonomic mobility for the user.
Furthermore, most of the prior art consists of exoskeletons which have their load bearing design directed on the outside of the leg, which is not compatible with the human biomechanics and which may cause serious injuries to the user. See for instance U.S. Pat. No. 8,474,672 B1 (Keith) and U.S. Pat. No. 8,968,222 B2 (Kazerooni et al.), or U.S. patent application No. US 2013/0303950 A1 (Angold et al.).
Therefore, despite ongoing developments in the field of load-carrying exoskeletons, there is a need for novel biomimetic non-powered load-carrying exoskeletons that can mitigate some of the shortcomings of the prior art.